5GHz indoor OFDM system using 4-element array antenna with analog phase shifter

5GHz band wireless LAN system in indoor environment suffers from multi-path distortion. It causes an attenuation of received power and frequency selective spectrum distortion. In this paper, we describe an array antenna system with analog phase shifter that has the robustness for the multi-path distortion. The proposed array antenna system is low cost and is not complex in the control circuit. We evaluate the error rate performance of OFDM system using our array antenna system by the computer simulation and the experimental measurement in indoor wireless LAN system. The computer simulation uses the channel frequency response based on the result from ray tracing. We specify our array antenna system only controls the direction of carioid beam pattern, and we compare our system performance with the performance of antenna selective diversity. The indoor experimental results show our system has better packet error performance with small footprint.